Apparatus for connecting or repairing flat workpieces

ABSTRACT

A device for applying a thermoplastic adhesive carrying thread across a joint or gap in sheet material such as wood veneer, consists of a body with a handle, a pressing member and a thread reel container, the pressing member having a heater. In action the thread is drawn from a reel in the container, passed down a guide tube to the front of the presser, and applied to the veneer by moving the device forward by hand whilst pressing it downwards on to the veneer. The device may have auxiliary pressing and guide rollers, and the presser foot may be shaped so that backward movement thereof cuts off a length of thread after its application to the veneer.

United States Patent -Biewald Apr. 1, 1975 APPARATUS FOR CONNECTING OR 2,468,965 5/1949 Ekstrom 219/214 x REPAIRING FLAT WORKPIECES 2,624,068 1/1953 Dobry 156/389 X 2,709,742 5/1955 Perry 219/244 X [75] Inventor: Heinz B e ald, e Ge y 2,906,847 9/1959 Grevich 156/583 x 3,547,735 12/1970 Ortel 156/545 X [73] Asslgnee' gfwg' g fi 3,660,206 5/1972 0:161 156/545 FOREIGN PATENTS OR APPLICATIONS [22] Filed 1973 1,054,735 /1953 France 156/577 [21] App]. No.: 407,624

Primary ExaminerA. Bartis Foreign Application Priority Data 57 ABSTR CT Apr. 16, 1973 Austria 3374/73 1 1 A A dev1ce for applying a thermoplastic adhes1ve carry- 521 US. Cl 219/243, 156/166, 156/320, ing thread across ajoim or 8 9 in sheet material Such 156/499 15 /545 15 577 39 230 219/23 as Wood veneer, consists Of a body with a handle, a [51] Int CLWHOSb 1/00, B65c 11/00, B32b/31/20 pressing member and a thread reel container, the [58] Field Of Search ..219/214, '221, Pressing member having a heateraction the thread 219/227 228, 230 231, 240, 243, 244 is drawn from a reel in the container, passed down a 236 239; 15 /577 499 322 320 5 2 5 3 guide tube to the front Of the presser, and applied to 579 389, 166, 5 55 the veneer by moving the device forward by hand whilst pressing it downwards onto the veneer. The de- [56] References Cited vice may have auxiliary pressing and guide rollers, and the presser foot may be shaped so that backward l 136 497 Z 'T PATENTS [56/582 X movement thereof cuts off a length of thread after its wa ow 2,123,415 7/1938 Gorbatenko 156/499 apphcauo to the Veneer 2,235,704 3/1941 G'orbatenko et a1 219/214 X 8 Claims, 3 Drawing Figures APPARATUS FOR CONNECTING OR REPAIRING FLAT WORKPIECES PRIOR APPLICATION In Austria on the April 16, 1973 and numbered A 3374/73 The present invention relates to a device which can be used for connecting flat workpieces together or for repairing tears in a flat workpiece. The flat workpieces may be veneers, pieces of wood, pieces of cardboard or any other suitable material.

The device of the present invention is intended to be used in conjunction with a connecting thread which effects the connection or repairing of the workpieces. It is an object of the invention to provide a device which enables the thread to be reliably applied to the veneer parts in a simple manner, and which severs the thread which has been applied from the remaining thread without necessitating separate cutting tools.

In accordance with the present invention, there is therefore provided a device for butt-connecting flat workpieces such as veneers or repairing damaged flat workpieces comprising a carrier body provided with a handle portion, a storage receptacle, capable of receiving at least one roll of thread provided with a thermoplastic adhesive coating located on said carrier body, a pressing member having heating means associated therewith adapted to soften the thermoplastic adhesive and to apply the thread and softened adhesive in a direction transverse to the longitudinal direction of the butt-connection or of the damaged portion of the workpiece, to the workpiece when the device is moved in a first direction and guide means adapted to guide the thread into the immediate vicinity of the pressing member, forward of the pressing member in the direction of travel of the device in which the thread and adhesive are applied to the workpiece.

Preferably, the pressing member has a heatconducting body, which is substantially cylindrical, one end of the pressing member being formed as a foot, which foot is adapted to apply the thread and adhesive to the workpiece or workpieces and flatten the thread and adhesive thereon in the said first direction of travel of the device, the foot being adapted to cause severance of the thread when the device is moved in a direction opposite to said first direction.

Advantageously, the foot has a flat or convexly curved end face which is adapted to engage the thread, said end face extending over the whole width of the pressing member and forming an extension thereof in the said first direction.

Further preferably, the pressing member is connected to an electrical heating device mounted on the carrier body.

Further advantageously, a pressing roller is rotatably mounted on the carrier body rearwardly, relative to said first direction, and spaced apart from said pressing member.

The device in accordance with the present invention is simple in structure and therefore relatively cheap to manufacture and make it possible, in a simple, rapid and reliable manner, to connect veneer sections together or torepair of damaged veneers. This is effected by cementing thereon a connecting thread, the thread being preferably applied, in short sections, at right angles to the longitudinal axis of the join or tear.

The invention will be further described, purely by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a side view of a device for connecting or repairing flat workpieces in accordance with the present invention;

FIG. 2 is a side view of a part of the device shown in FIG. 1 and on an enlarged scale relative thereto, and

FIG. 3 is a plan view of part of two butt-joined veneers showing their interconnection and repair after using the device in accordance with the present invention.

In FIG. 1, there is shown a device in accordance with the present invention which is used for connecting or repairing veneer parts 10, which may be in the form of strips or sheets, or other flat workpieces made of suitable material such as wood, wood material or cardboard. The device comprises a carrier body 12 provided with a handle portion 1 1. A storage receptacle 13 capable of receiving at least one roll 15 of a connecting thread 14, which thread is coated with an adhesive 14a is mounted on handle portion 13 of the carrier body 12.

Also located on the carrier body 12 is at least one pressing member 18 which presses the connecting thread 14 over the butt joint 16 between two adjacent veneer parts 10 or over a crack 17 in a veneer part 10. The member 18 is somewhat similar to a soldering iron. It is heated so as to soften the thermoplastic adhesive 14a and to press the thread over the joint 16 or crack 17. A guide member 21 guides the connecting thread 14 so that it is located in front of the pressing member 18 in the direction of travel of the device in the direction of the arrow shown in FIGS. 1 and 2.

The pressing member 18 has a heat-conducting body, and is therefore preferably made of metal, and is substantially cylindrical in shape.

The lower free end face of the pressing member 18 is formed into a foot 19. This foot opens out the connecting thread 14 on the joint between the veneers 10, and flattens it in the direction of travel of the device. When the device is suddently drawn back in the opposite direction, the foot severs the thread which has been adhesively applied to the join or crack from the remaining thread. The foot extends over the whole width to which the thread and adhesive has been expanded and has a flat or convexly curved lower end face 19a which acts as the pressing surface.

The substantially cylindrical pressing member 18 is connected to an electrical heating device 20 mounted on the carrier body 12. As shown, the member 18 is surrounded by the heating device 20 and is heated thereby by conduction and/or radiation.

The thread guide 21 is preferably in the form of a tube, more particularly, capillary tube, as is secured on the front (in the direction of travel) face of the pressing member 18 and is heated both by conduction from the member 18 and radiation from the heating device 20. This causes a preliminary softening of the adhesive prior to its application to the join or crack.

The thread 14 is drawn off from a roll, ball or reel 15 through a small aperture 27 in the base of the receptacle l3 and enters the top end of the guide tube 21. It is pre-heated whilst passing therethrough. The guide tube 21 follows the contours of the pressing member 18 and abuts thereagainst over a portion of the pressing member 18. The lower end of the guide tube terminates a short distance above the pressing surface 19a of the foot 19 so that the thread 14 thus supplied is exposed to the pressing surface 19a.

Rearwardly, in the direction of travel of the device, and slightly spaced apart from the pressing member 18, a rotatable pressing roller 22 is mounted on the carrier body 12, preferably by means of a cantilever arm 25. This rolls the thread 14 flattened by the foot 19 and simultaneously cools it.

Located against the underside of the pressing roller 22 is a scraper 23, preferably in the form of a blade. The scraper 23 is kept under tension by securing means 23a such as a screw, and scrapes particles of thread or adhesive residues from the pressing roller 22.

The scraper 23 is retained on the support body 22a for the roller which itself is mounted on the arm 25. Moreover, the carrier body 12 has mounted thereon two lateral rollers 24 connected in series which are located rearwardly in the direction of travel of the device, of the pressing roller 22.

The handle portion 11 is inclined diagonally upwardly in the direction of travel of the device. At its lower end, the handle portion 11 is detachably secured to the carrier body 12 and at its upper end, has one end of a support arm 26 mounted thereon. On the other end of the support arm 26, the receptacle 13 for the roll of thread is mounted. This receptacle is generally cup or basket-shaped. The roll 15 of thread 14 is loosely inserted in this receptacle 13 and releases the connecting thread 14 in a downwardly direction toward the pressing member 18 through a small aperture 27 in the base of the receptacle 13.

An electrical lead 28 connects the device to a source of electrical power. For safety reasons, the lead extends rearwardly (in the direction of travel) from the rear end of the device remote from the pressing member 18.

The device in accordance with the present invention enables the butt-connection of veneer parts to be effected and also allows cracks or slits in veneers to be repaired. The threads 14 together with its adhesive 14a is cemented onto the join or crack in a direction transverse to the longitudinal direction of the joint or break. The connecting thread 14 is pre-coated with the adhesive 14a and during its passage through the guide tube 14, it is heated by the heating device 20, which causes some of the adhesive to soften to a paste.

The thus pre-heated thread 14 and adhesive 14a, by displacing the device in the direction of the arrow, then arrives below the pressing surface 19a of the foot 19 where the heat supplied to the pressing member 18 causes all of the adhesive to soften into a paste. At the same time, the pressure applied to the handle causes the thread 14 to be pressed onto the veneers 10. The adhesive 14a is spread out thereby to form a flat strip on the veneers 10. The thread 14 is also flattened by the heat and the pressure applied to the adhesive. On cooling the adhesive sets, thereby firmly connecting the two veneers together, or the two parts of a damaged veneer.

FIG. 3 shows the flattened thread 14, and adhesive 14a overlapping, in the form of a strip, the butt joint 16 between two veneers and the cracks 17 in a damaged veneer.

The thread 14 is applied in individual sections on the veneers 10 so as to slightly overlap each side of the joint 16 or crack 17. When a joint 16 or crack 17 has been coated in a direction transverse to the longitudinal direction of the joint or crack, the device is suddenly retracted in a direction opposite to that shown by the arrow and hence causes a severing of the thread 14 applied to the join or crack from the remaining thread 14.

In a further embodiment, not shown, two or more connecting threads 14, each of which being unwound from a separate roll 15, and passing through a separate guide 21 are simultaneously adhesively applied to the veneers 10 by a common pressing member 18.

I claim:

1. A device for butt-connecting or repairing flat workpieces, comprising:

an elongated carrier body;

a handle mounted by one end adjacent an end of said carrier body;

a storage receptacle capable of receiving at least one roll of thread with a thermoplastic adhesive coating thereon, located on the other end of said handle, a pressing member;

heating means for said pressing member mounted transversely of said carrier body at the other end thereof; and

guide means located on said pressing member to guide said thread to a position forward of said pressing member in the direction of travel of said device when in use; and

wherein said heating means is a hollow cylindrical heat-conducting body, and said pressing member is secured within said body and has an external foot adapted to apply said thread and adhesive to said workpiece or workpieces, flatten said thread and adhesive thereon in the said direction of travel, and cause severance of said thread when said device is moved in a direction opposite to said direction of travel.

2. A device as recited in claim 1, wherein said foot has a slant end face adapted to engage said thread, said end face extending over the whole width of said pressing member.

3. A device as recited in claim 1, including an electrical heating device for said heating means.

4. A device as recited in claim 1, wherein said guide means comprises a tube at least a portion of which is mounted on said pressing member such that said tube extends forwardly (in said direction of travel) of said pressing member and is heated therby.

5. A device as recited in claim 4, wherein the upper end of said tube is spaced apart from said pressing member, and the lower end is secured to said pressing member such that the lower end of said tube terminates adjacent to, but spaced apart from, the lower end of said pressing member.

6. A device as recited in claim 1 comprising a pressing roller rotatably mounted on a cantilevered arm extending from said carrier body at a point rearward of said pressing member, the lower surface of said pressing roller lying behind and substantially in the same plane as the lower end of said pressing member.

7. A device as recited in claim 6 including a scraper mounted on said pressing roller arm, and means for resiliently pressing said scraper against said roller.

8. A device as recited in claim 1 including two lateral guide rollers mounted one on each side of said carrier body, said guide rollers being located rearward of said pressing roller. 

1. A device for butt-connecting or repairing flat workpieces, comprising: an elongated carrier body; a handle mounted by one end adjacent an end of said carrier body; a storage receptacle capable of receiving at least one roll of thread with a thermoplastic adhesive coating thereon, located on the other end of said handle, a pressing member; heating means for said pressing member mounted transversely of said carrier body at the other end thereof; and guide means located on said pressing member to guide said thread to a position forward of said pressing member in the direction of travel of said device when in use; and wherein said heating means is a hollow cylindrical heatconducting body, and said pressing member is secured within said body and has an external foot adapted to apply said thread and adhesive to said workpiece or workpieces, flatten said thread and adhesive thereon in the said direction of travel, and cause severance of said thread when said device is moved in a direction opposite to said direction of travel.
 2. A device as recited in claim 1, wherein said foot has a slant end face adapted to engage said thread, said end face extending over the whole width of said pressing member.
 3. A device as recited in claim 1, including an electrical heating device for said heating means.
 4. A device as recited in claim 1, wherein said guide means comprises a tube at least a portion of which is mounted on said pressing member such that said tube extends forwardly (in said direction of travel) of said pressing member and is heated therby.
 5. A device as recited in claim 4, wherein the upper end of said tube is spaced apart from said pressing member, and the lower end is secured to said pressing member such that the lower end of said tube terminates adjacent to, but spaced apart from, the lower end of said pressing member.
 6. A device as recited in claim 1 comprising a pressing roller rotatably mounted on a cantilevered arm extending from said carrier body at a point rearward of said pressing member, the lower surface of said pressing roller lying behind and substantially in the same plane as the lower end of said pressing member.
 7. A device as recited in claim 6 including a scraper mounted on said pressing roller arm, and means for resiliently pressing said scraper against said roller.
 8. A device as recited in claim 1 including two lateral guide rollers mounted one on each side of said carrier body, said guide rollers being located rearward of said pressing roller. 